From the Dark Ages to the Enlightenment
After the fall of Rome, the civilizations of the West lapsed into a span of roughly 500 years which are referred to as the “Dark Ages,” because much of the knowledge amassed by the great ancient cultures was lost, and social innovation was frozen. It was a disorganized and brutal period. Few people were trained to read or write, and most lived as peasants or laborers.
Fifty percent of children died before adulthood. The Dark Ages were a period of social instability... In the West, the church was a powerful force of order.
Throughout this period, most European countries/societies were not economically efficient enough to support large populations, and with only small spurts of growth, they remained stagnant for many generations.